Electronically tracking a path history

ABSTRACT

Methods and systems for electronically tracking the progress of teams as they cover an assigned geographic area are described herein. A server computer establishes a coverage area, divides the coverage area into a plurality of regions, and assigns each region to a team. Each team carries a tracking device capable of autonomously determining its present location without user assistance, thus allowing the team to focus on the assigned task, such as searching for a missing person, plowing a field, paving a road, etc. The server monitors the location of each tracking device as each team covers its assigned region, and updates on a visually displayed geographic map a historical path associated with each tracking device based on the monitored location of each tracking device. In this manner, users can quickly view the visual depiction of the historical to determine as yet uncovered areas.

FIELD OF THE INVENTION

The invention relates generally to electronic tracking of pathstraversed by a person or vehicle. More specifically, the inventionprovides a method and system for electronically tracking paths traversedand visually displaying the path history to illustrate areas which haveand have not been traversed.

BACKGROUND OF THE INVENTION

Search and rescue operations commence whenever a person is reported asmissing. The search and rescue operations typically entail identifyingor approximating a last known location of the missing person, andinitiating a physical search based on the identified position. However,there often is a lack of accurate recordkeeping of those areas that havebeen searched, resulting in the same area being searched twice, and notsearching altogether in other areas (i.e., there are gaps in the searcharea).

Similarly, farmers often have difficulty ensuring that an entire fieldhas been prepared for planting, or even that seed has been thrown overan entire field during the planting process. Road crews often manuallykeep track of sections of road that have been treated or prepared forsome work to be done, and thus often miss sections of road entirely, andtreat or prepare other sections twice.

Thus, it would be an advancement in the art to provide a location-basedtracking system that can detect and monitor a person or vehicle'shistorical path and visually display the path history to illustrate areathat have been traversed by the person or vehicle versus those areasthat have not been traversed by the person or vehicle.

BRIEF SUMMARY OF THE INVENTION

The following presents a simplified summary of the invention in order toprovide a basic understanding of some aspects of the invention. Thissummary is not an extensive overview of the invention. It is notintended to identify key or critical elements of the invention or todelineate the scope of the invention. The following summary merelypresents some concepts of the invention in a simplified form as aprelude to the more detailed description provided below.

To overcome limitations in the prior art described above, and toovercome other limitations that will be apparent upon reading andunderstanding the present specification, an aspect of the presentinvention is directed to method for tracking a history of searchpatterns of a search and rescue operation. The method may includeestablishing a search area based on a last known location or point ofdisappearance of a missing person, dividing the search area among searchteams each equipped with an appropriate tracking device as describedherein, monitoring the location of each search team's tracking device aseach search team searches its assigned region, and updating on avisually displayed geographic map a search trail associated with eachsearch team's tracking device based on the monitored location of eachsearch tracking device.

According to another aspect of the invention, a tracking device mayinclude a processor, a transceiver for communicating with a search andrescue control center, a display screen for outputting a visuallydisplayed geographic map, and memory storing computer executableinstructions which, when executed by the processor, cause the trackingdevice to perform a method for tracking a history of search patterns ofa search and rescue operation. The method may include determining asearch region of the tracking device and displaying the search region onthe visually displayed geographic map; monitoring, at regular intervals,a location of the tracking device as it is carried by a search teamsearching the search region; and updating the visually displayedgeographic map with a search trail corresponding to the monitoredlocation of the tracking device.

According to another aspect of the invention, a search and rescuecommand center may use a computer system having a processor controllingoverall operation of the system, a display device that outputs a visualdepiction of a geographic map of a search area, and memory storingcomputer executable instructions for performing a method for tracking ahistory of search patterns of a search and rescue operation. The methodmay include establishing the search area; dividing the search area intoa plurality of regions; assigning each region to one of a plurality ofsearch teams, wherein each search team is associated with a trackingdevice; monitoring a location of each tracking device as each searchteam searches its assigned region; and updating on the visual depictionof the geographic map of the search area a search trail associated witheach search tracking device based on the monitored location of eachtracking device in the monitoring step.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the present invention and theadvantages thereof may be acquired by referring to the followingdescription in consideration of the accompanying drawings, in which likereference numbers indicate like features, and wherein:

FIG. 1 illustrates a network architecture that may be used for one ormore aspects of the invention according to an illustrative embodiment ofthe invention.

FIG. 2 illustrates a block diagram of a tracking device according to anillustrative embodiment of the invention.

FIG. 3 illustrates a flow chart for tracking search patterns accordingto an illustrative embodiment of the invention.

FIG. 4 illustrates a search area according to an illustrative embodimentof the invention.

FIG. 5 illustrates a divided search area according to an illustrativeembodiment of the invention.

FIG. 6 illustrates another divided search area according to anillustrative embodiment of the invention.

FIG. 7 illustrates a composite search map according to an illustrativeembodiment of the invention.

FIG. 8 illustrates a tracking device screen display according to anillustrative embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

In the following description of the various embodiments, reference ismade to the accompanying drawings, which form a part hereof, and inwhich is shown by way of illustration various embodiments in which theinvention may be practiced. It is to be understood that otherembodiments may be utilized and structural and functional modificationsmay be made without departing from the scope of the present invention.

One or more aspects of the invention may be embodied incomputer-executable instructions, such as in one or more programmodules, executed by one or more computers or other devices. Generally,program modules include routines, programs, objects, components, datastructures, etc. that perform particular tasks or implement particularabstract data types when executed by a processor in a computer or otherdevice. The computer executable instructions may be stored on a computerreadable medium such as a hard disk, optical disk, removable storagemedia, solid state memory, RAM, etc. As will be appreciated by one ofskill in the art, the functionality of the program modules may becombined or distributed as desired in various embodiments. In addition,the functionality may be embodied in whole or in part in firmware orhardware equivalents such as integrated circuits, field programmablegate arrays (FPGA), and the like.

FIG. 1 illustrates a sample network architecture that may be used toperform one or more aspects of the invention. In FIG. 1, multipletracking devices 103 a-103 g (collectively and generically referred toas tracking device 103) have wireless communications capabilities tosend and receive data. Each tracking device 103 may be any device thathas two-way data communications, for example, a mobile phone, personaldigital assistant, smart phone, tablet- or pen-based computer, laptop orpalmtop computer, or other suitable device. Tracking devices 103 maycommunicate through wireless communication towers 105 a, 105 b, 105 c(collectively/generically, 105). Each wireless communication tower 105is operated by a wireless network operator 107 a, 107 b(collectively/generically, 107) to relay communications to and from acommand center server 111, and/or others, via a data network 109, suchas the Internet. Those of skill in the art will appreciate that variousnetwork architectures and topologies may be used to accomplish the sameor similar goals as described herein. For example, instead of aterrestrial wireless communications system, one or more tracking devicesmay communicate via a satellite based wireless communication system, andone or more towers 105 may be replaced with one or more satellites (notshown).

According to an illustrative embodiment of the invention, one or more oftracking devices 103 may be a STORM HAWK® brand handheld GPS mobileinformation system available from WeatherData, Inc. of Wichita, Kans.According to another illustrative embodiment of the invention, one ormore of tracking devices 103 may be a device as described in Smith, U.S.Pat. No. 6,845,324, issued Jan. 18, 2005, herein incorporated byreference in its entirety for all purposes. Those of skill in the artwill appreciate that any device having the requisite capabilities asdescribed herein may be used.

FIG. 2 illustrates a block diagram of a generic tracking device 103 thatmay be used according to an illustrative embodiment of the invention.Tracking device 103 may have a processor 203 for controlling overalloperation of the tracking device and its associated components,including RAM 205, ROM 207, input/output module 209, location module211, transceiver 213, and memory 215.

I/O 209 may include a keypad, touchscreen, and/or stylus through which auser of device 103 may provide input, and may also include one or moreof a speaker for providing audio output and a video display device forproviding textual, audiovisual and/or graphical output.

Location module 211 determines the location (e.g., latitude, longitude,and/or altitude) of the tracking device 103. Location module 211 mayinclude a global position system (GPS) receiver to autonomouslydetermine the location of the tracking device using the commerciallyaccessible GPS satellite network. Alternatively, when a network operatorproviding wireless telecommunication services to tracking device 103 isequipped with E911 location detection capabilities (e.g., mobile devicelocation determination by time difference of arrival (TDOA), angle ofarrival (AOA), and/or triangulation technologies, etc.) location module211 may query the network operator for the location of the trackingdevice 103. In such a manner, the methods and systems described hereinare usable with devices capable of autonomously determining their ownlocation, as well as with devices that work in a network which candetermine the location of individual devices with reasonablespecificity.

Transceiver 213 includes any component that enables tracking device 103to wirelessly communicate via antenna 214 with a wirelesstelecommunications network provided by a network provider. Memory 215may store software used by tracking device 103, such as an operatingsystem 217, application programs 219, and associated data 221. Forexample, one application program 221 used by tracking device 103according to an illustrative embodiment of the invention may be atracking client application 223, which communicates directly orindirectly with a tracking manager application resident on a centralserver, such as server 111 (FIG. 1). As described herein, trackingmanager is described synonymously with server 111.

The initial example of an illustrative embodiment described below iswith respect to search and rescue operations, and is not intended tolimit the application of the invention to search and rescue operations,but rather illustrates one of a variety of uses of the presentinvention. Subsequent examples will follow.

With reference to FIG. 1 and FIG. 3, a tracking manager on server 111may provide overall management of multiple tracking devices 103 assearch and rescue operations commence for a missing person. FIG. 3illustrates a flowchart of a search and rescue management methodperformed by server 111 according to an illustrative embodiment of theinvention. Server 111 may be any computing device that can send andreceive communications, directly or indirectly, between multipletracking devices 103, for example, via the Internet 109 and via one ormore network operators 107.

Server 111 initiates the method in step 301 upon receiving informationregarding a base point, here a point of disappearance of a missingperson, around which a coverage area will be determined. The point ofdisappearance may be entered manually as determined or approximated by ahuman user, or may be calculated automatically based on knowninformation regarding a know path of travel of the missing person and anamount of time since last contact with the missing person. With furtherreference to FIG. 4, once the point of disappearance 401 is determined,the server 111 in step 303 establishes a coverage area 403 (a searcharea in the present example) based on the point of disappearance.

For example, the server 111 may establish a circular search area 403around the point of disappearance 401 with a radius r, where r is basedon an estimated amount of time t lapsed since the missing person wasestimated to be at the point of disappearance and a rate or speed oftravel s with which the missing person is estimated to be moving. Thus,in one example, the radius r may be calculated using the formula r=t×s.Those of skill in the art will appreciate that the search area may be ashape other than circular, and may be established based on othercriteria. For example, a rectangular search area may be used, and thesize of the search area may be based on a known area in which themissing person is located, rather than based on an amount of lapsed timet and a speed s.

Once the search area 403 has been established, the server 111 in step305 divides the search area into a plurality of sub-regions (searchregions in the present example), and assigns each region to a team(search teams in the present example). Each search team includes one ormore people or devices that physically cover an assigned region, andthat have a tracking device 103 among them. FIG. 5 illustrates acircular search area 403 split into pie-shaped search regions in such asmanner that search teams fan out from the point of disappearance 401.FIG. 6 illustrates an alternative split of search area 403 into a gridof search regions.

In step 307, while search teams are searching their respectivelyassigned search regions, each team's tracking device monitors thetracking device's current location and reports the location to thetracking manager at regular intervals. With further reference to FIG. 7,based on the location information received in step 307, the server instep 309 updates a visually depicted geographic map 701 of the coveragearea displayed on a display device connected to server 111. The term‘connected,’ as used herein, includes both direct connections as well asindirect connections that pass data through one or more intermediatenodes, devices, hops, etc., before reaching the intended destination.

Map 701 may include a visual representation of the coverage area 403, aswell as visual cues on the map 701 regarding the search status of eachsearch region, here grid cells A1, A2, A3, A4, B1, B2, B3, B4, C1, C2,C3, C4, D1, D2, D3, and D4. The visual cues displayed on map 701 mayinclude an indication that a region has been fully covered (in thepresent example, searched), such as is illustrated in FIG. 7 for cellsA1, A4, B3, and C1, an indication that a region has not yet been coveredat all, such as is illustrated for cells D1, D2, and D3, or anindication that progress in a region is underway, such as is illustratedfor cells A2, A3, B1, B2, B4, C2, C3, C4, and D4.

According to an illustrative embodiment of the invention, the visual cueindicating that a search of a region is underway may include ahistorical trail of a search path undertaken by the search teamassociated with that region. For example, each of cells A2, A3, B1, B2,B4, C2, C3, C4, and D4 are illustrated with such a historical trail.Each historical trail may be color coded (not illustrated) to correspondto a specific search party. In addition, the width of the historicaltrail drawn may vary depending on the size of the search party, toaccount for the width searched by the search party based on its numberof people. For example, the trail in cell B2 may represent a searchparty consisting of a single individual, the trail in cell C3 mayrepresent a search party consisting of two individuals, and the trail incell C2 may represent a search party consisting of three individuals.

The width of the historical trail may also be adjusted based on otherfactors, such as the visibility or elevation of the searcher. Forexample, the width might be narrowest for a searcher on foot in aforest, wider for a searcher on horseback in a cornfield, and widerstill for a helicopter based search. The width of the search trail mightbe narrowed proportionately if a search is conducted in low visibilityconditions, such as in fog or blowing dust or sand. In one embodimenteach tracking device has a GPS attachment with an accuracy within 8feet, and thus the minimum width is representative of 8 feet. In otherembodiments where location can be determined with greater specificity,e.g., as location technology improves, the trail width may be evennarrower. The maximum trail width is limited only by visibility of thesearch team to which a tracking device is assigned.

Upon the occurrence of certain predefined conditions, the server 111 maychange a visual representation of a search region to indicate the entireregion has been covered. According to an illustrative embodiment of theinvention, for example, the server may automatically change a region toindicate it has been completely covered when the historical trailrepresents or indicates that the team assigned to that region has beenwithin a predefined distance of every point within that region. If thetrail is drawn to indicate those points of which the search team hasbeen within the predefined distance, the server 111 may detect when aregion is completely filled in by the historical trail and then indicatethat the region has been completely covered. Other criteria mayalternatively be used, for example, when a percentage of the region isfilled up and/or there are no gaps in the region larger than apredefined size and/or width. For example, assuming the team assigned tocell A2 continues its current search pattern, server 111 may indicatethat the region has been completely covered in approximately fouradditional back-and-forth cycles. In some embodiments the server 111might leave the historical trail displayed, or provide a query button toallow a user of the server 111 to view a search trail after the serverhas marked a region as having been completely covered.

In step 311 each team's tracking device may be updated to display thehistorical trail of its own path, such as is illustrated in FIG. 8.Thus, between steps 309 and 311, maps are updated both on a displayassociated with the coordinating central server 111, as well as ondisplays associated with each tracking device 103. FIG. 8 illustrates asample screen 801 of a tracking client application on a tracking device103 associated with the team assigned to cell A3 of FIG. 7. Those ofskill in the art will appreciate that not all devices capable ofproviding information to tracking manager 111 may be capable ofdisplaying information such as is illustrated in FIG. 8, depending onthe features of the tracking device 103 (e.g., screen size, graphicscapabilities, etc.). Screen 801 may include a visual representation ofthe team's historical path 803, and may include an icon or graphic 805indicating the team's assigned region in relation to the entire searcharea. Screen 801 may also include an indication 807 of the currentregion, and one or more buttons 809, 811 for other applicationfunctionality, e.g., menu, reporting options, features, etc.

In an illustrative embodiment, button 809 may be used, e.g., to togglebetween the maps illustrated in FIG. 7 and FIG. 8 where server 111 sendsinformation to the tracking device 103 regarding other tracking devices.Button 811 may be used to obtain an options menu, e.g., to report thatan objective is complete (e.g., that the missing person has been found),to send a custom message other than indicating that the objective iscomplete, to request an update of other tracking device's progress (ifnot automatically received), to quit the application, etc. For example,where a tracking device is equipped with a camera (not shown), an optionmight include sending a time-stamped, location-stamped digitalphotograph depicting someone or something found by the search team.Another option might include reporting hazardous or medical conditionsvia one or more data messages as taught in U.S. Pat. No. 6,845,324.

In step 313 server 111 determines whether the objective is complete(i.e., whether the missing person has been found, in this example),e.g., by determining whether server 111 has received a message from anytracking device indicating that the missing person has been found. Ifthe objective is complete, the method ends. If the objective is notcomplete, then in step 315 the server 111 determines whether there isany coverage area remaining to be covered. If so, then server 111 cyclesthrough steps 307-317 again, as applicable. If not, then in step 317 theserver 111 expands the coverage area (preferably incrementally each timestep 317 is encountered) and cycles through steps 305-317 again, asapplicable.

Those of skill in the art will appreciate that not all steps need beperformed in the recited order, and one or more steps may be optional.For example, the order of steps 309 and 311 is immaterial, and step 317may be optional. In other embodiments, step 303 may be delayed orskipped altogether, and search teams may begin searching prior to theestablishment of an official search area. In such an embodiment, asearch team may provide input into a tracking device to begin trackingbased on the search team's present location. Thus, a search team canbegin searching upon reaching an anticipated search area without waitingfor the server to establish search regions for each search team. Oncethe server establishes search regions, tracking devices associated withteams that have already begun searching may upload their data regardingareas already searched. These are merely examples of step reordering andoptional steps, and are not intended to limit the steps which can bereordered or omitted.

Various modifications and permutations are foreseen and consideredwithin the spirit and scope of the invention. For example, each trackingdevice may (alternatively or in addition to the server 111) determinewhen the tracking device has completely searched its assigned region,and output an alert to the user or team member holding the device,and/or send a message to the tracking manager informing that the regionhas been searched. The message may also optionally request anothersearch region, if any are left, or such a request may be sent in aseparate message.

In addition, when any tracking device sends a message to the trackingmanager that a missing person has been found, the tracking manager mayrelay the message to all tracking devices, and inform each team whetherany missing persons remain to be located, or whether the search has thusended because all missing persons have been found. The system may thusbe easily modified for use with multiple missing persons at a time.

The methods and systems described herein may also be used for otheroperations where ensuring that a person or vehicle traverses an entirepredefined area can be useful to the success of the operation. Forexample, a farmer may carry a tracking device 103 in each tractorworking a field to ensure that the entire field gets worked.Alternatively, the farmer may use a single tracking device not incommunication with a server, but rather one that manages its ownprogress and historical path information as described herein (i.e., hasa standalone mode), or the farmer may even use multiple tracking devicesin a peer-to-peer mode or configuration without the use of a centralserver, where each tracking device communicates with the other trackingdevices. Use by a farmer to ensure coverage of a field is also anexample of scenario in which steps 301 and/or 303 (FIG. 3) areunnecessary, because the coverage area may already be known (i.e., thefield). The objective in such a scenario may simply be to cover theentire field, and thus either of method steps 313 and 315 may be usedfor this determination, rendering the other method step unnecessary inthis example, as well as method step 317.

In another similar example, road crews may carry a tracking device oneach paver, bulldozer, steamroller, or other piece of maintenanceequipment to ensure that every part of a road is properly maintained.Again, a single road crew might carry a single tracking device instandalone mode, may use multiple tracking devices in peer-to-peer mode,or may use multiple tracking devices managed by a server, thus allowinga management center (e.g., a state's Department of Transportation) toensure that the work is completed properly over an entire portion ofroad.

Other illustrative uses include finding stray livestock, locating aweapon of mass destruction (e.g., based on known partial informationsuch as the geographically-assigned prefix of a telephone numberassigned to a landline telephone used to make a suspicious telephonecall), and locating a missing train in “dark territory” (i.e., territorywhere there is no signaling system that keeps track of the train'slocation).

The present invention includes any novel feature or combination offeatures disclosed herein either explicitly or any generalizationthereof. While the invention has been described with respect to specificexamples including presently preferred modes of carrying out theinvention, those skilled in the art will appreciate that there arenumerous variations and permutations of the above described systems andtechniques. Thus, the spirit and scope of the invention should beconstrued broadly as set forth in the appended claims.

1. A method for electronically tracking a historical path, said methodcomprising: (a) establishing a coverage area; (b) dividing the coveragearea into a plurality of regions; (c) assigning each region to one of aplurality of teams, wherein each team is associated with a trackingdevice; (d) receiving electronic transmissions from each tracking deviceas each team traverses its assigned region, wherein each electronictransmission includes a location of the tracking device from which it isreceived; and (e) updating on a geographic map displayed on a computerdisplay device a historical path associated with each tracking devicebased on the monitored locations in step (d), wherein a width of eachhistorical path corresponds to a size of the team to which thehistorical path corresponds.
 2. The method of claim 1, furthercomprising the step of: (f) when any team has finished covering itsassigned region, updating the finished region on the geographic mapdisplayed on the computer display device to indicate it has beencompleted.
 3. The method of claim 1, further comprising automaticallyassigning a new region to a team that has finished covering its assignedregion.
 4. The method of claim 1, wherein step (a) comprisesestablishing a circular area around a point of disappearance.
 5. Themethod of claim 4, wherein step (b) comprises dividing the circular areainto cells.
 6. The method of claim 1, wherein step (e) comprisesrendering each historical path with a different visual appearance on thevisually displayed geographic map.
 7. The method of claim 1, furthercomprising: (f) receiving a message from one of the plurality oftracking devices indicating that an objective has been completed,wherein said message comprises a location in which the objective wascompleted.
 8. The method of claim 7, further comprising: (g)automatically sending a response message to tracking devices other thanthe one tracking device from which the message was received, saidresponse message indicating that the objective has been completed.
 9. Acomputer readable medium storing computer executable instructions forperforming the method of claim
 1. 10. The method of claim 1, wherein thesize comprises a number of people.
 11. The method of claim 2, furthercomprising: (g) determining that a team has finished covering itsassigned region by analyzing the team's corresponding current historicalpath.
 12. The method of claim 11, wherein in step (g) analyzing theteam's corresponding current historical path comprises determining thatthe team has been within a predefined distance of every location withinthe team's assigned region.
 13. The method of claim 11, wherein in step(g) analyzing the team's corresponding current historical path comprisesdetermining that the historical path covers a predefined minimumpercentage of the team's assigned region.
 14. The method of claim 13,wherein the predefined minimum percentage is one-hundred percent. 15.The method of claim 11, wherein in step (g) analyzing the team'scorresponding current historical path comprises determining that thereare no gaps in the historical path larger than a predefined maximumallowed gap size.
 16. The method of claim 15, wherein the predefinedmaximum gap size comprises a maximum allowed gap width.
 17. The methodof claim 1, further comprising the step of outputting an alert by atracking device when the tracking device determines that its assignedteam has finished covering the team's assigned region.
 18. A trackingdevice, comprising: a processor, a display screen for outputting avisually displayed geographic map; memory storing computer executableinstructions which, when executed by the processor, cause the trackingdevice to perform a method for electronically tracking a historicalpath, said method comprising: (a) determining a geographic region to bemonitored by the tracking device and displaying the region on thevisually displayed geographic map; (b) monitoring at regular intervals,a location of the tracking device as it is carried by a team coveringthe assigned region; and (c) updating the visually displayed geographicmap with a historical path corresponding to the monitored locations ofthe tracking device, wherein a width of the historical path correspondsto a size the team.
 19. The tracking device of claim 18, furthercomprising a location module capable of determining the location of thetracking device, and wherein step (b) comprises receiving the locationfrom the location module.
 20. The tracking device of claim 18, whereinstep (b) comprises receiving the location from a wireless networkoperator.
 21. The tracking device of claim 18, wherein step (b)comprises wirelessly sending the location of the tracking device to aserver.
 22. The tracking device of claim 18, wherein the computerexecutable instructions further comprise displaying on the displayscreen a graphic indicating the region of the tracking device ascompared with a coverage area corresponding to multiple trackingdevices.
 23. The tracking device of claim 18, wherein the computerexecutable instructions further comprise: (d) receiving coverageinformation corresponding to a plurality of tracking devices; (e)displaying on the display screen a coverage area, wherein the coveragearea is divided in regions bases on the received coverage information;and (f) displaying in each region a historical path corresponding to amonitored location of a tracking device associated with that region, asreceived in the coverage information, wherein a width of each historicalpath corresponds to a size of the team to which the historical pathcorresponds.
 24. The tracking device of claim 18, wherein the computerexecutable instructions further comprise: (d) automatically detecting,based on step (b), when the team has completed covering its assignedregion, and outputting an alert as a result of the detection.
 25. Thetracking device of claim 24, wherein step (d) comprises determining whenan entire field has been covered by a piece of farming machinery. 26.The tracking device of claim 24, wherein step (d) comprises determiningwhen a search and rescue team has searched its assigned region.
 27. Thetracking device of claim 24, wherein step (d) comprises determining whena road crew has treated a predefined portion of a road.
 28. The trackingdevice of claim 18, wherein the computer executable instructions furthercomprise: (d) receiving user input indicating that an objective has beencompleted prior to covering the entire assigned region; and (e)automatically sending a message to a server based on step (d).
 29. Thetracking device of claim 18, wherein the computer executableinstructions further comprise: (d) receiving a message indicating thatan objective has been completed; and (e) outputting an alert as a resultof step (d).
 30. The tracking device of claim 18, wherein step (a)comprises receiving geographic region information as input from a userof the tracking device.
 31. The tracking device of claim 18, furthercomprising a transceiver, and wherein step (a) comprises wirelesslyreceiving geographic region information from a server.
 32. The trackingdevice of claim 18, further comprising a transceiver, and wherein themethod for electronically tracking a historical path further comprisescommunicating location information via the transceiver between thetracking device and a second tracking device.
 33. The tracking device ofclaim 18, wherein step (a) comprises receiving user input identifyingthe geographic area.
 34. The tracking device of claim 18, wherein step(a) comprises receiving user input identifying the geographic area basedon a present location of the tracking device.
 35. A computer system,comprising: a processor controlling overall operation of the system; adisplay device that outputs a visual depiction of a geographic map of asearch area; memory storing computer executable instructions forperforming a method for tracking a history of search patterns of asearch and rescue operation, said method comprising: (a) establishingthe search area based on a point of disappearance; (b) dividing thesearch area into a plurality of regions; (c) assigning each region toone of a plurality of search teams, wherein each search team isassociated with a tracking device; (d) monitoring a location of eachtracking device as each search team searches its assigned region; (e)updating on the visual depiction of the geographic map of the searcharea a search trail associated with each search tracking device based onthe monitored location of each tracking device in step (d); (f)receiving user input indicating that a missing person has been foundprior to searching the entire assigned region; and (g) automaticallysending a message to a server based on step (f), including a location inwhich the missing person was found.